I was going to build the same thing a while ago but never actually built it. I’m not sure if is the easiest way to do it but it uses easily obtainable parts.
As bogdanfirst said if you use a decoder then the decoder can only address one led at a time, which makes for a pretty boring project. So you can use flip-flops to give the leds a sort of basic memory. But it does mean that you need a flip-flop for every led. Once the decoder addresses the specific led then the flip-flop will toggle and what ever state it was (i.e. on or off) it will change to the opposite.
So if you want to turn led number 8 on then you simply pass the number 8 into the decoder through the parallel port of the computer which is connected to the decoder. The decoder will then send a high signal to the corresponding flip-flop. This flip-flop will then change from a low to a high output (assuming it was originally on low). To turn the 8th led back off you pass another number to the decoder to make the input of the flip-flop goes low (the led will still be on) and then address the 8th led again causing the flip-flop to toggle and change back to low (or off). I hope that wasn’t too confusing.
I quickly made the schematic below but it is not complete, I have only put two leds on the decoder. Your version would probably have a larger decoder and a flip-flop led pair on ever output of the decoder. I also don’t know what flip-flop or decoder you should use, these ones were just the first ones I found in the parts list, maybe someone could quote some specific part names that could be used.
Please ask if you need any more help of if you are confused on how the flip-flops or circuit works.